5 Common Physics Misconceptions Among Students

Physics is a little bit different than other science fields because many students develop different ideas by misinterpreting physics concepts written in text books. Let’s take the reference of a simple example. Students think that everything that goes up must come down or gravitational force is the only thing that’s preventing us from flying etc. There’s a problem when these things are concerned. The problem is that most of them are not right. In this article, we’ll go through a few Physics misconceptions that arise frequently in students.

1. Every moving body will eventually come to a “rest”

This is one of the most common physics misconceptions. “Rest” is considered to be the natural state of all body. This misconception arises due to Newton’s first law of motion. Newton’s first law of motion states that “Everything at rest will stay at rest, and everything in motion will stay in motion, unless acted upon by an external force.”

The first part of the statement seems quite reasonable. Anything that’s at rest will stay at rest unless an external force acts upon it. Students usually find no problem with this first part. It’s the 2nd part that creates the problem. Students aren’t comfortable with the second part because they have developed that idea that “rest” is the natural state of a body. A rolling ball will certainly come to a rest at some point even if no fielder gets into the path of the ball. They develop this idea because they disregard the invisible forces that are in action. One of those invisible forces is friction who plays a big role in bringing the body to rest. So, the 2nd part of Newton’s 1st law of motion is correct because a moving body will keep moving unless an external force acts upon it.

2. A continuous force is required for continuous motion

This misconception comes up as a result of the 1st point. You might think like that while pushing a shopping cart in a supermarket that a continuous force is necessary to keep the cart in motion. But that’s only because of the presence of friction. If the same cart is pushed in outer space, it would keep moving forever because space is mostly empty and the absence of frictional force in space keeps the cart moving forever.

3. A heavy object is hard to push

This is another misconception that’s quite common among students. A heavy object is really hard to push, there’s no doubt about it. But do remember that the weight of the object doesn’t play an important factor for the same. Inertia/mass is factor for which it’s so difficult to push a heavy object.

To know about the difference between mass and weight, you can refer to this video-

4. Planets move around the sun due to gravity

One thing to remember is that gravity is the weakest of all forces. The reason for which planets move around the Sun is that the planets were already moving within the protoplanetary disk. Gravity just keeps the planets within the orbit.

5. Lighter objects take more time to fall than heavier objects

This misconception is curbed by Galileo long ago in his experiment performed at the Leaning Tower of Pisa. Both the objects will take the same amount of time to come to the ground unless there’s the presence of an external force. Students actually disregard the presence of external force while coming to this wrong conclusion. A lighter object usually takes more time to fall than a heavier one because the two objects move through air, thereby experiencing air resistance. Air resistance is more in case, of a lighter object. Thus, the lighter object takes more time to fall than the heavier one. This concept is finally proved by the famous feather and hammer drop experiment shown in the video below.

Misconceptions aren’t a problem. We have to make these parts of a problem into a part of the solution. The best way to do that is to highlight these misconceptions as much as possible so that students become aware that these are actually wrong. Professional tutors can definitely look into it for your child’s benefit. With that, we’ll sign off for now. Hope you had a good read.

Sudipto Das

Sudipto writes technical and educational content periodically for wizert.com and backs it up with extensive research and relevant examples. He's an avid reader and a tech enthusiast at the same time with a little bit of “Arsenal Football Club” thrown in as well. He's got a B.Tech in Electronics and Instrumentation.
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